In general, an air conditioner is a device for cooling or heating an indoor area by using a refrigerating cycle of a refrigerant including a compressor, a condenser, an expansion instrument, and an evaporator in order to provide an agreeable and comfortable indoor environment to users.
In an air conditioner, an evaporator is configured to heat-exchange water and a refrigerant, a cold water coil through which water heat-exchanged with the refrigerant passes is provided, and when an air blower circulates indoor air to the cold water coil, air heat-exchanged with water cools the indoor area.
When the air conditioner operates, the compressor is turned on, and when the air condition is stopped, the compressor is turned off. When the compressor is turned on, cold water cools air to cool the indoor area, and here, when the degree of discharge superheat of the compressor is high, efficiency is lowered and a liquid refrigerant flows into the compressor.